They also found that, after six weeks of supplementation, the study participants also experienced increased muscle mass.

The study, backed by the research arm of Danone-owned, medical nutrition company Nutricia​​, was published​​ in the peer-reviewed Journal of Nutrition​. Researchers came from the University of Clermont Auvergne, the University Hospital Clermont-Ferrand, VU University Medical Center in Amsterdam, as well as Danone’s Nutricia Research.

It investigated the benefits of medical nutrition product FortiFit Pro, which is marketed for the dietary management of disease-related malnutrition and must be used under medical supervision.

“We hypothesized that supplementing breakfast with this medical nutrition drink would enhance muscle protein synthesis and thus enhance muscle mass over a longer period of time,”​ the researchers wrote.

Study Design: Men over 65 years​

According to the researchers, protein consumption for breakfast averages between 5g and 10g, which is insufficient for maximal muscle protein synthesis, which was the logic behind the current study’s focus on supplementing breakfast.

Healthy men aged over 65 years with a BMI between 20 and 30 were eligible for inclusion. The exclusion of women allowed minimal variation of changes in muscle mass. Researchers also excluded participants taking medication that affects gastrointestinal function or muscle metabolism.

Participants were randomly assigned to receive either the vitamin D and leucine-enriched whey protein medical nutrition drink, which has 20g of protein, 3g of total leucine, 9g of carbohydrates, and 3g of fat, or a flavored watery placebo.

Results: Increased lean mass in the limbs​

Researchers measured the nutritional status and physical activity of participants at the beginning and end of the studies. During these visits, participants filled out a questionnaire to assess physical activity and mental performance, and a muscle biopsy from the vastus laterali muscle was collected for baseline analysis.

After the sixth week of intervention, researchers noted a significant gain in lean mass of the limbs of test group participants compared to the placebo group.

Through questionnaire responses, the researchers identified that there were no changes in physical activity between both groups from beginning of the study period to the end. “Few studies have investigated the effect of nutritional intervention without exercise on longer-term muscle outcomes related to sarcopenia ​[also known as muscle loss],”​ the researchers argued.

There were multiple limitations, such as only being able to collect a biopsy at beginning of study due to local ethical restrictions. Moreover, the researchers recommend future studies to look at muscle protein breakdown and oxidation measurements, as the current one only looked at muscle protein synthesis.

But the findings unveiled some benefits of supplementing breakfast with a vitamin D and leucine-enriched whey protein drink for the older population.

“This nutritional intervention resulted in a more evenly distributed protein intake over the day and increased skeletal muscle mass after six week of intervention in healthy older adults,”​ they wrote. “Our study shows that supplementing breakfast with a vitamin D and leucine-enriched w hey protein medical nutrition drink may be a way to support muscle preservation in older people.”​